Hi,
Check the reports before the upgrade like below.
1) Run the reports in BI for a particular user having authorization and other user having full access
2) Run the reports in BO same as like above. ( Complexity will be more if your BO is using BICS).
After the upgrade, check the above is working as per the expectations.
Most important to check the prompts/ variables values for the users. after the upgrade, we faced issues as BI authorizations are not extended for BICS even though PAM say supported